It is a powerful poison that is found in two almost totally unrelated kinds of animal: puffer fish and newts. It has been serving as a tool in nerve physiology and may provide a model for new local anesthetics

It is a material in which quantum phenomena play an important role in determining gross properties. Nonetheless, in a surprising number of cases its behavior resembles that of an ordinary classical solid

He stands out among 17th-century natural philosophers as a careful observer and investigator. Particularly in pneumatics and chemistry, his experiments laid a firm groundwork for much that was to follow

The fact that less than 5 percent of the U.S. labor force is engaged in agriculture reflects a high degree of mechanization. The machines harvest not only grains but also such crops as fruits and vegetables

Some fossils represent the tracks or burrows of ancient animals. Such fossils can seldom be identified with a particular animal, but they do show how the animal behaved and something of how behavior evolved